1. Field of the Invention
The subject invention is directed to a resilient metallic gasket, and more particularly, to a metallic gasket assembly for use between opposed pipe flanges which has a reusable base plate and a replaceable spring energized sealing ring.
2. Background of the Related Art
Resilient metallic gaskets are well known in the art and have been utilized in a variety of high performance sealing applications. For example, U.S. Pat. No. 4,114,907 to Abbes et al. discloses a resilient metal gasket of toroidal configuration having a central core consisting of a resilient helical spring that is surrounded by a deformable envelope of metal or plastic. In use, the spring provides an elastic recovery force against a crushing stress applied to the outer envelope to enhance the sealing characteristics of the device. Because the outer envelope is plastically deformed during service, the entire device must be discarded after its first use.
U.S. Pat. No. 4,381,869 to Abbes et al. discloses a resilient metallic gasket having two sealing lines interconnected by a structural template. The two sealing lines consist of contiguous helical springs that are surrounded by a ductile metal casing. Once again, the outer metal casing is plastically deformed during service. Thus, the entire device must be discarded after its first use. It would be beneficial therefore, to provide a resilient metallic gasket that has reusable components so as to provide a cost advantage over prior art sealing devices of this type.
The subject invention is directed to a new, useful and cost-effective sealing device, and more particularly, the subject invention provides a high performance gasket assembly for use on rough surfaced flanges throughout a broad range of seating loads. The gasket assembly of the subject invention includes a reusable annular base plate having an inner periphery and opposed upper and lower surfaces, and a replaceable spring energized sealing ring that is releasably retained within the inner periphery of the base plate.
The sealing ring includes at least one resilient spring element surrounded by a deformable jacket that extends beyond the upper and lower surfaces of the base plate to conform to surface irregularities in the flange surfaces upon compression of the gasket between the flange surfaces. Accordingly, the jacket is comprised of a material having a greater ductility than the flange surfaces.
Preferably, an annular groove extends radially outwardly from the inner periphery of the base plate, between the upper and lower surfaces thereof, for retaining a radially outer portion of the sealing ring. The jacket has a radially outwardly extending annular flange releasable retained within the annular groove of the base plate. The annular groove is defined at least in part by a retainer ring releasable engaged within the inner periphery of the base plate. In one embodiment of the invention, the retainer ring is releasably engaged to the base plate by an interference fit, and in another embodiment the retainer ring is a compressible c-ring. Alternative retention means may also be employed.
In accordance with a preferred embodiment of the subject invention, the gasket assembly includes an annular base plate having an inner periphery and opposed upper and lower surfaces. An annular groove extends radially outwardly from the inner periphery of the base plate between the opposed upper and lower surfaces thereof. A spring energized sealing ring is operatively associated with the inner periphery of the base plate and includes at least one resilient sealing element surrounded by a deformable jacket. The jacket has a radially outwardly extending annular flange releasably retained within the annular groove of the base plate. The jacket extends beyond the upper and lower surfaces of the base plate to conform to surface irregularities in the flange surfaces upon compression of the gasket between the flange surfaces.
The subject invention is also directed to a gasket assembly for use between adjacent flange surfaces that includes an annular base plate having an outer periphery, an inner periphery, and opposed upper and lower surfaces, and includes a stepped annular groove. The annular groove extends radially outwardly from the inner periphery of the base plate between the opposed upper and lower surfaces thereof. The annular groove has an upper step adjacent the upper surface of the base plate and a lower step adjacent the lower surface of the base plate.
The gasket assembly further includes a spring energized sealing ring operatively associated with the inner periphery of the base plate and including at least one resilient spring element surrounded by a ductile jacket. The jacket extends beyond the upper and lower surfaces of the base plate to conform to surface irregularities in the flange surfaces upon compression of the gasket between the flange surfaces, and the jacket has a radially outwardly extending annular flange. The gasket further includes a retainer structure, such as a ring releasably engaged with the upper step of the base plate in such a manner so that the annular flange of the jacket is retained between the retainer ring and the lower step of the base plate.
It is envisioned that the spring energized sealing ring of the subject invention may be employed either alone or in combination with the base plate. Accordingly, the subject invention is also directed to a sealing device for use between adjacent flange surfaces which includes first and second radially adjacent annular spring elements and a deformable jacket surrounding the first and second annular spring elements. The jacket is formed from a material having a greater ductility than the flange surfaces so that it conforms to surface irregularities in the flange surfaces upon compression between the flange surfaces.
These and other aspects of the subject invention and the method of using the same will become more readily apparent to those having ordinary skill in the art from the following detailed description of the invention taken in conjunction with the drawings described hereinbelow.